Whatever Happened to H1N1 (Swine Flu) and HIV? New Answers at CROI 2010

A Blog Entry From CROI 2010

By Anjali SanghviFrom TheBodyPRO

Feb. 19, 2010; 10:15 a.m. Pacific Time

The H1N1 pandemic that swept the world in 2009 caused plenty of panic and media hype. But given the small amount of available data on H1N1 at the time, HIV care providers were left with more questions than answers, including whether H1N1 acquisition risk was higher for HIV-infected people, whether H1N1 infection was more severe in HIV-infected people, and whether the H1N1 vaccine would be as effective in HIV-infected patients as in HIV-uninfected patients. A series of posters presented here at CROI 2010 answers some of those questions.

There were three key take-away messages from the posters:

H1N1 was not worse in, and did not worsen, HIV. In HIV-infected people with well-managed conditions (good CD4+ cell counts, low viral loads), H1N1 was not more severe than it was in the general population, according to the research presented by Esteban Martinez of Hospital Clínic de Barcelona. In addition, H1N1 did not appear to have any negative impact on the CD4+ cell counts or viral loads of HIV-infected patients. People with advanced HIV disease, however, did appear to face a higher risk for experiencing potentially life-threatening complications from H1N1 infection.

Don't confuse H1N1 with an opportunistic infection. HIV-infected patients who had opportunistic respiratory infections and were infected with H1N1 often got diagnosed and treated for the opportunistic infection, but not the H1N1, leading to complications and even death, according to research presented by Gustavo Reyes-Terán of Instituto Nacional de Enfermedades Respiratorias in Mexico City. His team determined that in 25% of cases, the symptoms of the opportunistic infection were masking the H1N1 symptoms. Reyes-Terán recommended that any HIV-infected patient who presents with respiratory illness should either be tested for H1N1 (if a rapid test is available) or treated empirically for the flu.

Bickel added, however, that there appeared to be signs that when the H1N1 vaccine was administered in two doses (as was originally intended; subsequent studies in the general population suggested one dose was enough), the vaccine worked just as well for HIV-infected populations as the single dose worked in the general population. This data was not processed in time to be included in his poster presentation at CROI, Bickel said. He urged more study to confirm the findings.

In general, the HIV-infected population has never fared as well as the general population with influenza vaccines. But the difference in rates of failure with a single dose of H1N1 vaccine when comparing HIV-infected patients to the general population was much greater than it normally is with the seasonal flu vaccine.

Based on the findings of his study, Bickel suggested that HIV-infected people needed to be considered, and researched, as a separate group from the general population when studying vaccinations in the future.

(Please note: Your name and comment will be public, and may even show up in Internet search results. Be careful when providing personal information! Beforeadding your comment, please read TheBody.com's Comment Policy.)

Please do not modify the following input field.

Your Name:

Your Location:

(ex: San Francisco, CA)

Your Comment:

Characters remaining:

Please note: Knowledge about HIV changes rapidly. Note the date of this summary's publication, and before treating patients or employing any therapies described in these materials, verify all information independently. If you are a patient, please consult a doctor or other medical professional before acting on any of the information presented in this summary. For a complete listing of our most recent conference coverage, click here.

The Body is a service of Remedy Health Media, LLC, 750 3rd Avenue, 6th Floor, New York, NY 10017. The Body and its logos are trademarks of Remedy Health Media, LLC, and its subsidiaries, which owns the copyright of The Body's homepage, topic pages, page designs and HTML code. General Disclaimer: The Body is designed for educational purposes only and is not engaged in rendering medical advice or professional services. The information provided through The Body should not be used for diagnosing or treating a health problem or a disease. It is not a substitute for professional care. If you have or suspect you may have a health problem, consult your health care provider.